Java tutorial
/******************************************************************************* * Copyright (c) 2000, 2008 IBM Corporation and others. * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * * Contributors: * IBM Corporation - initial API and implementation * Sebastian Davids <sdavids@gmx.de> - Fix for bug 90273 - [Dialogs] * ListSelectionDialog dialog alignment *******************************************************************************/ package org.eclipse.buckminster.jnlp.p2.ui.certificates; import java.util.ArrayList; import java.util.Iterator; import org.eclipse.jface.dialogs.Dialog; import org.eclipse.jface.dialogs.IDialogConstants; import org.eclipse.jface.viewers.CheckboxTableViewer; import org.eclipse.jface.viewers.ILabelProvider; import org.eclipse.jface.viewers.IStructuredContentProvider; import org.eclipse.swt.SWT; import org.eclipse.swt.events.SelectionAdapter; import org.eclipse.swt.events.SelectionEvent; import org.eclipse.swt.events.SelectionListener; import org.eclipse.swt.layout.GridData; import org.eclipse.swt.layout.GridLayout; import org.eclipse.swt.widgets.Button; import org.eclipse.swt.widgets.Composite; import org.eclipse.swt.widgets.Control; import org.eclipse.swt.widgets.Shell; /** * A standard dialog which solicits a list of selections from the user. This class is configured with an arbitrary data * model represented by content and label provider objects. The <code>getResult</code> method returns the selected * elements. * <p> * This class may be instantiated; it is not intended to be subclassed. * </p> * <p> * Example: * * <pre> * ListSelectionDialog dlg = new ListSelectionDialog(getShell(), input, new BaseWorkbenchContentProvider(), * new WorkbenchLabelProvider(), "Select the resources to save:"); * dlg.setInitialSelections(dirtyEditors); * dlg.setTitle("Save Resources"); * dlg.open(); * </pre> * * </p> * * @noextend This class is not intended to be subclassed by clients. */ public class ListSelectionDialog extends SelectionDialog { // the root element to populate the viewer with private Object inputElement; // providers for populating this dialog private ILabelProvider labelProvider; private IStructuredContentProvider contentProvider; // the visual selection widget group CheckboxTableViewer listViewer; // sizing constants private final static int SIZING_SELECTION_WIDGET_HEIGHT = 250; private final static int SIZING_SELECTION_WIDGET_WIDTH = 300; /** * Creates a list selection dialog. * * @param parentShell * the parent shell * @param input * the root element to populate this dialog with * @param contentProvider * the content provider for navigating the model * @param labelProvider * the label provider for displaying model elements * @param message * the message to be displayed at the top of this dialog, or <code>null</code> to display a default * message */ public ListSelectionDialog(Shell parentShell, Object input, IStructuredContentProvider contentProvider, ILabelProvider labelProvider, String message) { super(parentShell); setTitle("Selection Needed"); inputElement = input; this.contentProvider = contentProvider; this.labelProvider = labelProvider; if (message != null) { setMessage(message); } else { setMessage("Select the items:"); } } /* * (non-Javadoc) Method declared on Dialog. */ @Override protected Control createDialogArea(Composite parent) { // page group Composite composite = (Composite) super.createDialogArea(parent); initializeDialogUnits(composite); createMessageArea(composite); listViewer = CheckboxTableViewer.newCheckList(composite, SWT.BORDER); GridData data = new GridData(GridData.FILL_BOTH); data.heightHint = SIZING_SELECTION_WIDGET_HEIGHT; data.widthHint = SIZING_SELECTION_WIDGET_WIDTH; listViewer.getTable().setLayoutData(data); listViewer.setLabelProvider(labelProvider); listViewer.setContentProvider(contentProvider); addSelectionButtons(composite); initializeViewer(); // initialize page if (!getInitialElementSelections().isEmpty()) { checkInitialSelections(); } Dialog.applyDialogFont(composite); return composite; } /** * Returns the viewer used to show the list. * * @return the viewer, or <code>null</code> if not yet created */ protected CheckboxTableViewer getViewer() { return listViewer; } /** * The <code>ListSelectionDialog</code> implementation of this <code>Dialog</code> method builds a list of the * selected elements for later retrieval by the client and closes this dialog. */ @Override protected void okPressed() { // Get the input children. Object[] children = contentProvider.getElements(inputElement); // Build a list of selected children. if (children != null) { ArrayList list = new ArrayList(); for (int i = 0; i < children.length; ++i) { Object element = children[i]; if (listViewer.getChecked(element)) { list.add(element); } } setResult(list); } super.okPressed(); } /** * Add the selection and deselection buttons to the dialog. * * @param composite * org.eclipse.swt.widgets.Composite */ private void addSelectionButtons(Composite composite) { Composite buttonComposite = new Composite(composite, SWT.NONE); GridLayout layout = new GridLayout(); layout.numColumns = 0; layout.marginWidth = 0; layout.horizontalSpacing = convertHorizontalDLUsToPixels(IDialogConstants.HORIZONTAL_SPACING); buttonComposite.setLayout(layout); buttonComposite.setLayoutData(new GridData(SWT.END, SWT.TOP, true, false)); Button selectButton = createButton(buttonComposite, IDialogConstants.SELECT_ALL_ID, SELECT_ALL_TITLE, false); SelectionListener listener = new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { listViewer.setAllChecked(true); } }; selectButton.addSelectionListener(listener); Button deselectButton = createButton(buttonComposite, IDialogConstants.DESELECT_ALL_ID, DESELECT_ALL_TITLE, false); listener = new SelectionAdapter() { @Override public void widgetSelected(SelectionEvent e) { listViewer.setAllChecked(false); } }; deselectButton.addSelectionListener(listener); } /** * Visually checks the previously-specified elements in this dialog's list viewer. */ private void checkInitialSelections() { Iterator itemsToCheck = getInitialElementSelections().iterator(); while (itemsToCheck.hasNext()) { listViewer.setChecked(itemsToCheck.next(), true); } } /** * Initializes this dialog's viewer after it has been laid out. */ private void initializeViewer() { listViewer.setInput(inputElement); } }